<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<script>
			var p=prompt("请输入一个数字","1");
			//var p=parseInt(n)+1;
			//alert(p);
			 
			if(!isNaN(p))
			{
				p=parseFloat(p)+1;
				alert(p);
			}else{
				alert("您输入的有问题");
			}
			
		</script>
	</head>
	<body>
	</body>
</html>
